Geertz, Clifford.  1973.  “Religion as a Cultural System,” in The Interpretation of Cultures.  New York:  Basic Books, p. 90.

…a religion is:

(1) a system of symbols which acts to

(2) establish powerful, pervasive, and long-lasting moods and motivations in men by

(3) formulating conceptions of a general order of existence and

(4) clothing these conceptions with such an aura of factuality that

(5) the moods and motivations seem uniquely realistic.